This invention relates to a method and apparatus for automatically advancing sheet material such as terry cloth toweling along its length from a supply to a transfer station, cutting segments of the sheet material in the transfer station from the supply, then moving the cut segment of the sheet material in a path parallel to its cut ends, and hemming the cut ends as the sheet material moves. More particularly, the invention comprises a method and apparatus for aligning the untufted laterally-extending bands or hem spaces of terry cloth toweling as the toweling is moved from a supply toward a cut and transfer station, in such a manner that the untufted bands are straightened and accurate cuts are made through the bands at positions equidistance between the plush areas of the toweling.
In the manufacture of terry cloth towels and other flat goods, a common procedure is to move the tufted toweling along its length from a supply and to cut across its length to form the goods in segments. A popular design for terry cloth towels is to have the main body of the terry cloth towel include a plush tufted surface of terry cloth, and then at the opposite ends of the towel to have one or more bands of or hem spaces of untufted toweling which are of lesser thickness than the plush portion of the towel. The terry cloth toweling is initially manufactured in a very long length, and the supply of terry cloth toweling material is advanced along its length and cut through the untufted bands to form the individual towel segments. The cut untufted bands are later folded and sewn into a hem.
In the past a supply of terry cloth towel material has been cut into towel segments by hand, by a worker moving the towel material along a work surface, locating the thin bands of the towel material, and then cutting across the toweling through the bands. Typically, a motorized cutting implement is used which includes a rotatable cutting disk and the worker moves the implement along the thin bands of toweling material to cut the material. This is a slow operation, requires a skilled worker, and occasionally results in improper cuts being made in the toweling material. It is very difficult for the worker to cut exactly parallel to the filler threads of the material.
Another prior art apparatus for cutting terry cloth toweling material through the thin bands extending laterally across the material includes an automated cutter wherein the supply of towel material is fed toward a cutting station between a pair of parallel rotatable rollers that engage the plush surfaces of the toweling to move the toweling to the cutter. The spacing of the rollers is greater than the thickness of the thin bands of the toweling material, so that the rotation of the rollers will not move the toweling material when the thinner bands are between the rollers. When a thin band of the toweling material is detected, the rollers are operated to run in the reverse direction and the rollers move the thick part of the toweling backwards along the feed path until the thin portion of the material is located between the feed rollers. This locates the thin portions of the material at the cutting station, and a cut is made across the material at a predetermined distance from the feed rollers. While this type of equipment functions to make a cut through the thin bands of the towel material, the equipment operates at a relatively low speed and the direction of movement of the toweling material must be reversed during each cutting cycle, and the equipment does not work well on relatively thin terry cloth material. Moreover, some terry cloth material is likely to have a pattern of several thin bands extending across the material so that the towel segment which is cut from the material will have a design at opposite ends of alternating long and short bands of thin material. It is difficult for some of the prior art automatic towel cutting equipment to distinguish between the long and short thin bands in the toweling material so as to make the cut in the long thin band and not in a short thin band.
Another prior art towel cutting device comprises a detecting system for locating bands formed in the terry cloth material that include no filler threads so that when a cut is made through these thin bands of a toweling material, a towel with a loose fringe is formed. The detection equipment includes a feeler that tends to fall through the areas of towel material that have no filler threads so as to locate the proper portion of a towel material where the cut is to be made. The detector tends to accumulate thread, lint, and debris and to become inoperable after the system has been operated for some period of time. Also, the detection system has not proven to be 100% reliable in that slack in one edge portion of the towel caused by nonuniform weaving of the material tends to cause an incorrect cut across the material.
Another prior art apparatus is disclosed in U.S. Pat. No. 4,375,175, wherein toweling material is advanced along its length to a cutting station and the thin bands of a toweling material are detected at opposite edges of the toweling material. The cutter is then angled so as to correspond with the angle of the thin band across the toweling material, the toweling material is stretched taut across its length so as to tend to remove the curvature from the thin band, and then the cut is made at the angle of the thin band across the toweling material.
Another prior art apparatus is disclosed in U.S. Pat. No. 4,437,369 which discloses apparatus that advances toweling material along its length to a cutter. Detectors at opposite sides of the path of the toweling material detect the thin bands through which the cut is to be made, and the toweling material is advanced from the detectors at each edge independently of the opposite edge so that the opposite ends of the thin band of the toweling material will be properly located at the cutter. The toweling is stretched across its length so as to remove the curvature of the thin band before the cut is made.
Although it has been recognized in the prior art that it is desirable to straighten the thin bands of toweling material before cutting through the toweling material, the prior art does not teach a method for aligning the thin bands of toweling material not only at the opposite edges of the toweling material but at several positions across the length of the toweling material in a simple, reliable and expedient manner.